Inducing Labor Linked to Increased C-Section Risk

< Jun. 23, 2010 > -- Experts have suspected for some time that induction of labor was associated with an increased risk for cesarean delivery (C-section). New research has put some hard and fast numbers to such a link.

The author of the new study is Dr. Deborah Ehrenthal, director of women's health programs at Christiana Care Health System in Newark, Del., and an assistant professor of family medicine at Jefferson Medical College of Thomas Jefferson University in Philadelphia. According to Dr. Ehrenthal, induction of labor doubles the risk of C-section.

The research appears in the July issue of the journal Obstetrics & Gynecology.

Medically Necessary vs. Elective

The decision to induce labor is often medically necessary, including situations in which it is deemed safer to deliver the baby than to continue the pregnancy. But many inductions are "elective," requested typically by a woman or her doctor, Dr. Ehrenthal found in her study. "There are concerns that deliveries are being scheduled [and labor-induced] for non-medical reasons."

Among the reasons for elective induction are women electing to have labor induced when their partner is available, such as being back in town from a business trip, says Dr. Ehrenthal.

"We need to understand it's not without risk to be doing this," Dr. Ehrenthal says of some elective inductions and the higher risk of C-sections. "There are significant risks to moms for C-sections."

C-Section Risk More than Doubled

In her study, Dr. Ehrenthal focused on 7,804 women giving birth for the first time who delivered single infants at term, between 37 and 42 weeks.

She found that labor was induced in 43.6 percent of the women. Of those inductions, 39.9 percent were elective inductions.

Dr. Ehrenthal next looked at the women who had C-sections and found that use of labor induction (whether elective or not) increased the odds of having a C-section by more than 2.6 times.

Put another way, "20 percent of the cesareans were attributed to the induction, whether elective or not," Dr. Ehrenthal says. "We need to be a little bit less ready to do an induction."

Of the 43.6 percent of women induced, she says, "it's a very high rate of induction."

Rate of Induction is Increasing

Inductions have been rising, said Dr. Caroline Signore, an obstetrician-gynecologist at the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD) at the US National Institutes of Health (NIH), who wrote an accompanying commentary in the journal.

In 1990, just 9.5 percent of US women had labor-induced deliveries, she writes, but the rate was 22.5 percent by 2006.

The new study, she says, puts a number on what experts suspected - that the rise in induced labors is driving the rise in C-sections - now at an all-time high of 32 percent of deliveries in the United States.

Elective inductions should not be done before 39 weeks' gestation, according to recommendations by the American College of Obstetricians and Gynecologists (ACOG), but that guideline is not rigorously followed, Dr. Signore notes. In the study, some of the women were induced as early as 37 weeks.

In 37 percent of the women induced, the cervix was not sufficiently ready for delivery, Dr. Ehrenthal found.

Having one C-section also increases the chances of having to have a C-section in later deliveries. "Emerging evidence shows increasing risk with increasing cesarean deliveries. Preventing the primary C-section can stop that cascade," and reducing elective labor inductions is one way to do that, she says.

Always consult your physician for more information.

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More About Cesarean Delivery (C-section)

Delivery is the moment when the fetus, followed by the placenta, exits the mother's body. Delivery can either be accomplished vaginally or by cesarean section (also called c-section).

If a woman is unable to deliver the fetus vaginally, the fetus is delivered surgically, by performing a C-section. This procedure is usually performed in an operating room or a designated delivery room. Some C-sections are planned and scheduled accordingly, while others may be performed as a result of complications that occur during labor.

Once the anesthesia has taken effect, an abdominal incision is made, and an opening is made in the uterus. The amniotic sac is opened, and the baby is delivered through the opening. The woman may feel some pressure and/or a pulling sensation.

Following the delivery of the baby, the physician will stitch the abdominal incision together and the mother is given oxytocin (either by an injection into the muscles or intravenously) to contract the uterus, thereby preventing bleeding from occurring.

There are several conditions which may make having a baby by cesarean section more likely. These include, but are not limited to, the following:

previous C-section

fetal distress

abnormal delivery presentation (i.e., breech, shoulder, face)

a labor that fails to progress or does not progress normally

placental complications (i.e., placenta previa, in which the placenta blocks the cervix and presents the risk of becoming detached prematurely from the fetus)

twins or other multiples

Always consult your physician for more information.

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